Thumb guard



FIG. 1 is a top front perspective view of a thumb guard showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a right side view thereof (the left side being a mirror view of the right side);

FIG. 5 is a front view thereof (the rear view being a mirror image of the front view); and,

FIG. 6 is a top view of the thumb guard shown in-use with the thumb guard positioned on a user's thumb.

The broken line portions of FIG. 6 depict environment that forms no part of the claimed design. 

CLAIM The ornamental design for a thumb guard, as shown and described. 